Role of ferrous iron chelator 2,2′-dipyridyl in preventing delayed vasospasm in a primate model of subarachnoid hemorrhage

1998 ◽  
Vol 88 (2) ◽  
pp. 298-303 ◽  
Author(s):  
Laura L. Horky ◽  
Ryszard M. Pluta ◽  
Robert J. Boock ◽  
Edward H. Oldfield
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Blood Clot ◽  
Autologous Blood ◽  
Iron Chelator ◽  
Preventive Therapy ◽  
Control Group ◽  
Primate Model ◽  
Content Type ◽  
Fine Print

Object. Oxyhemoglobin (HbO2) causes vasospasm after subarachnoid hemorrhage (SAH). The most likely spasmogenic component of HbO2 is iron. Various iron chelators, such as deferoxamine, have prevented vasospasm in vivo with limited success. However, only chelators of iron in the ferric state have been studied in animal models of vasospasm after SAH. Because free radical formation requires the ferrous (Fe++) moiety and Fe++ is a potent binder of the vasodilator nitric oxide, the authors hypothesized that iron in the ferrous state causes vasospasm and that chelators of Fe++, such as 2,2′-dipyridyl, may prevent vasospasm. This study was undertaken to investigate the influence of 2,2′-dipyridyl on vasospasm after induction of SAH in a primate model. Methods. Twelve cynomolgus monkeys were randomly divided into two groups and then both groups underwent placement of an arterial autologous blood clot in the subarachnoid space around the right middle cerebral artery (MCA). The five animals in the control group received intravenously administered saline and the seven treated animals received intravenously administered chelator (2,2′-dipyridyl) for 14 days. Sequential arteriography for assessment of MCA diameter was performed before and on the 7th day after SAH. Conclusions. Prevention of cerebral vasospasm by means of treatment with continuous intravenous administration of 2,2′-dipyridyl is reported in a primate model of SAH. This result provides insight into the possible mechanism of delayed vasospasm after aneurysmal SAH and provides a potential preventive therapy for it.

Temporal changes in perivascular concentrations of oxyhemoglobin, deoxyhemoglobin, and methemoglobin after subarachnoid hemorrhage

1998 ◽  
Vol 88 (3) ◽  
pp. 557-561 ◽  
Author(s):  
Ryszard M. Pluta ◽  
John K. B. Afshar ◽  
Robert J. Boock ◽  
Edward H. Oldfield
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Cerebral Vasospasm ◽  
Blood Clot ◽  
Saline Control ◽  
Control Group ◽  
Content Type ◽  
Delayed Cerebral Vasospasm ◽  
Arterial Blood ◽  
Fine Print

Hemoglobin released from hemolysed erythrocytes has been postulated to be responsible for delayed cerebral vasospasm after subarachnoid hemorrhage (SAH). However, the evidence is indirect and the mechanisms of action are unclear. Cerebrovascular tone is regulated by a dynamic balance of relaxing and contracting factors. Loss of the endothelium-derived relaxing factor—nitric oxide in the presence of oxyhemoglobin and overproduction of endothelin-1 stimulated by oxyhemoglobin have been postulated as causes of delayed cerebral vasospasm after SAH. Object. The authors aimed to investigate this hypothesis using in vivo microdialysis to examine time-dependent changes in the perivascular concentrations of oxyhemoglobin, deoxyhemoglobin, and methemoglobin in a primate model of SAH. Methods. Nine cynomolgus monkeys underwent right-sided frontotemporal craniectomy and placement of a semipermeable microdialysis catheter adjacent to the right middle cerebral artery (MCA). Saline (control group, three animals) or an arterial blood clot (SAH group, six animals) was then placed around the MCA and the catheter. Arteriographically confirmed vasospasm had developed in all animals with SAH but in none of the control animals on Day 7. The dialysate was collected daily for 12 days. Levels of oxyhemoglobin, deoxyhemoglobin, and methemoglobin were measured by means of spectrophotometry. Perivascular concentrations of oxyhemoglobin, deoxyhemoglobin, and methemoglobin peaked on Day 2 in the control monkeys and could not be detected on Days 5 to 12. Perivascular concentrations of oxyhemoglobin and deoxyhemoglobin peaked on Day 7 in the SAH group, at which time the concentrations in the dialysate were 100-fold higher than in any sample obtained from the control animals. Methemoglobin levels increased only slightly, peaking between Days 7 and 12, at which time the concentration in the dialysate was 10-fold higher than in samples from the control animals. Conclusions. This study provides in vivo evidence that the concentrations of oxyhemoglobin and deoxyhemoglobin increase in the cerebral subarachnoid perivascular space during the development of delayed cerebral vasospasm. The results support the hypothesis that oxyhemoglobin is involved in the pathogenesis of delayed cerebral vasospasm after SAH and implicate deoxyhemoglobin as a possible vasospastic agent.

Effects of the Ca++-permeable nonselective cation channel blocker LOE 908 on subarachnoid hemorrhage—induced vasospasm in the basilar artery in rabbits

2003 ◽  
Vol 98 (3) ◽  
pp. 561-564 ◽  
Author(s):  
Yoshifumi Kawanabe ◽  
Tomoh Masaki ◽  
Nobuo Hashimoto
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Intravenous Administration ◽  
Basilar Artery ◽  
Channel Blocker ◽  
Autologous Blood ◽  
Content Type ◽  
Dependent Part ◽  
Before And After ◽  
Fine Print

Object. The Ca++ influx into vascular smooth-muscle cells (VSMCs) plays a fundamental role in the development and chronic effects of vasospasm after subarachnoid hemorrhage (SAH). The Ca++-permeable nonselective cation channels (NSCCs) are activated by several endothelium-derived constricting factors such as endothelin 1 (ET-1) and thromboxane A2. Moreover, the receptor-operated Ca++ channel blocker LOE 908 inhibits ET-1—induced extracellular Ca++ influx via NSCCs in the VSMCs of the basilar artery (BA) and the NSCC-dependent part of ET-1—induced vasoconstriction of BA rings. The purpose of the present study was to evaluate the in vivo role of LOE 908 on SAH-induced vasospasm. Methods. Forty-two Japanese white rabbits were assigned to seven groups. Treatment groups consisted of the following: 1) control rabbits without SAH that received a cisternal injection of saline; 2) rabbits with SAH that were subjected to the intravenous administration of saline; 3 through 6) rabbits with SAH that underwent the intravenous administration of 0.01, 0.1, 1, or 10 mg/kg LOE 908, respectively; and 7) rabbits without SAH that underwent the intravenous administration of 10 mg/kg LOE 908. Autologous blood was injected into the cisterna magna. The caliber of the BA was measured on angiographic studies before and after the cisternal injection of autologous blood. The intravenous injection of LOE 908 inhibited the magnitude of an SAH-induced vasosapsm. In addition, the concentration of LOE 908 required to relax vasospasm (1 mg/kg) correlated with that required to block Ca++ influx into VSMCs. Conclusions. The Ca++ channel blocker LOE 908 may inhibit the magnitude of an SAH-induced vasospasm by blocking the influx of Ca++ through NSCCs in rabbit BAs. Blocking the NSCCs may represent a new treatment for cerebral vasospasm after SAH.

Prevention of vasospasm by anti-CD11/CD18 monoclonal antibody therapy following subarachnoid hemorrhage in rabbits

2004 ◽  
Vol 101 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Gustavo Pradilla ◽  
Paul P. Wang ◽  
Federico G. Legnani ◽  
Lynn Ogata ◽  
Gregory N. Dietsch ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Subarachnoid Hemorrhage ◽  
Autologous Blood ◽  
Rabbit Model ◽  
Control Group ◽  
Lymphocyte Function ◽  
Content Type ◽  
Basilar Arteries ◽  
Fine Print

Object. Adhesion of leukocytes and their migration into the periadventitial space may be critical in the pathophysiology of vasospasm following subarachnoid hemorrhage (SAH). The cell adhesion molecules involved in this process are lymphocyte function—associated antigen—1 (CD11a/CD18) and macrophage antigen—1 (CD11b/CD18), which are present on neutrophils/macrophages, and intercellular adhesion molecule—1 (CD54), which is present in endothelial cells. A humanized monoclonal antibody (mAb), Hu23F2G, targets CD11/CD18 and prevents leukocyte adhesion to endothelial cells. In this study, systemic administration of Hu23F2G prevented vasospasm in the rabbit model of SAH. Methods. Twenty-six New Zealand White rabbits were injected with autologous blood into the cisterna magna to induce SAH, after which they were randomized to receive injections of either Hu23F2G (10 animals) or a placebo at 30 minutes and 24 and 48 hours after SAH (six animals). Control animals underwent sham operations (four animals) or SAH alone (six animals). The animals were killed 72 hours after SAH, their bodies perfused and fixed, and their basilar arteries processed for morphometric analysis. Peripheral white blood cells (WBCs) were counted at 72 hours. The percentages of lumen patency were compared using the Student t-test. The presence of neutrophils and macrophages was confirmed by immunohistochemical analysis in which a rat anti—rabbit anti-CD18 mAb and cresyl violet were used. Treatment with Hu23F2G resulted in the significant prevention of vasospasm. Animals treated with Hu23F2G had 90 ± 7% lumen patency compared with 65 ± 7% in the placebo group (p = 0.025). The percentage of lumen patency in the SAH-only group was 59 ± 10%. The mean WBC count was 16,300 ± 2710/µl in the treatment group, compared with 7000 ± 386/µl in the control group (p = 0.02). Administration of Hu23F2G produced increased numbers of WBCs in 70% of the animals treated. Conclusions. This study supports the concept that leukocyte—endothelial cell interactions play an important role in the pathophysiology of chronic vasospasm after SAH. Systemic therapy with an anti-CD11/CD18 mAb prevents vasospasm after SAH by inhibiting adhesion of neutrophils and macrophages and their migration into the periadventitial space.

Neuropeptide Y in the primate model of subarachnoid hemorrhage

1992 ◽  
Vol 77 (3) ◽  
pp. 417-423 ◽  
Author(s):  
Ryszard M. Pluta ◽  
Anna Deka-Starosta ◽  
Alois Zauner ◽  
Jay K. Morgan ◽  
Karin M. Muraszko ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Neuropeptide Y ◽  
Cerebral Vasospasm ◽  
Primate Model ◽  
Content Type ◽  
Peripheral Plasma ◽  
Delayed Cerebral Vasospasm ◽  
Arterial Plasma ◽  
Fine Print

✓ The cause of cerebral vasospasm after subarachnoid hemorrhage (SAH) remains unknown. Recently, an association between the potent vasoconstricting peptide, neuropeptide Y, and delayed cerebral vasospasm after SAH has been postulated. This was based on the findings of increased neuropeptide Y levels in the cerebrospinal fluid (CSF) and plasma after SAH in animals and humans. For this study, the primate model of SAH was used to assess the possible role of neuropeptide Y in delayed vasospasm after SAH. Fifteen cynomolgus monkeys underwent placement of a clot of either whole blood or red blood cells in the subarachnoid space around the middle cerebral artery (MCA). Sequential arteriography for assessment of MCA diameter and sampling of blood and CSF for neuropeptide Y were performed: before SAH (Day 0); 7 days after SAH, when signs of delayed cerebral vasospasm peak in this model and in humans; 12 days after SAH; and 28 days after SAH. Subarachnoid hemorrhage did not evoke changes in CSF or plasma levels of neuropeptide Y. Nine monkeys had arteriographic evidence of vasospasm on Day 7, but no change in neuropeptide Y levels occurred in plasma or CSF. In addition, neuropeptide Y levels did not change, even after resolution of vasospasm on Day 12 or Day 28. Neuropeptide Y levels were substantially higher in CSF than in arterial plasma (p < 0.003 at each interval). No correlation was found between neuropeptide Y levels in CSF and in plasma. These results do not confirm a relationship between neuropeptide Y levels in the CSF or peripheral plasma and delayed cerebral vasospasm in SAH.

CSF leukotriene C4 following subarachnoid hemorrhage

1988 ◽  
Vol 69 (4) ◽  
pp. 488-493 ◽  
Author(s):  
Pietro Paoletti ◽  
Paolo Gaetani ◽  
Guido Grignani ◽  
Lucia Pacchiarini ◽  
Vittorio Silvani ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Subarachnoid Hemorrhage ◽  
Arterial Spasm ◽  
Lipoxygenase Pathway ◽  
Content Type ◽  
Symptomatic Vasospasm ◽  
Csf Levels ◽  
Fine Print

✓ Leukotrienes derive from arachidonic acid metabolism via the lipoxygenase pathway and modulate several cellular events. In the central nervous system, leukotrienes are mainly synthesized in the gray matter and in vascular tissues. Their production is enhanced in ischemic conditions and in experimental subarachnoid hemorrhage (SAH). Previous studies have indicated the ability of the leukotrienes C4 and D4 to constrict arterial vessels in vivo and in vitro and have suggested their involvement in the pathogenesis of cerebral arterial spasm. In the present study, the authors measured lumbar and cisternal cerebrospinal fluid (CSF) levels of leukotriene C4 in 48 patients who had suffered aneurysmal SAH. In 12 of the cases, symptomatic and radiological spasm was evident. The mean lumbar CSF level of immunoreactive-like activity of leukotriene C4 (i-LTC4) was significantly higher (p < 0.005) than in control cases, while the cisternal CSF level was higher than the lumbar mean concentration (p < 0.005). Patients presenting with vasospasm had significantly higher levels of i-LTC4 compared to patients without symptomatic vasospasm. This is the first report concerning monitoring of i-LTC4 levels in the CSF after SAH. The results of this study suggest that: 1) metabolism of arachidonic acid via the lipoxygenase pathway is enhanced after SAH; 2) the higher cisternal CSF levels of i-LTC4 may be part of the biological response in the perianeurysmal subarachnoid cisterns after the hemorrhage; and 3) the higher CSF levels of i-LTC4 in patients presenting with vasospasm suggest that a relationship exists between this compound and arterial spasm and/or reflect the development of cerebral ischemic damage.

Effect of intracarotid nitric oxide on primate cerebral vasospasm after subarachnoid hemorrhage

1995 ◽  
Vol 83 (1) ◽  
pp. 118-122 ◽  
Author(s):  
John K. B. Afshar ◽  
Ryszard M. Pluta ◽  
Robert J. Boock ◽  
B. Gregory Thompson ◽  
Edward H. Oldfield
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Cerebral Vasospasm ◽  
Primate Model ◽  
Content Type ◽  
Continuous Release ◽  
Blood Flow Velocities ◽  
The Right ◽  
Fine Print

✓ The continuous release of nitric oxide (NO) is required to maintain basal cerebrovascular tone. Oxyhemoglobin, a putative spasmogen, rapidly binds NO, implicating loss of NO in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). If vasospasm is mediated by depletion of NO in the vessel wall, it should be reversible by replacement with NO. To investigate this hypothesis, the authors placed blood clots around the right middle cerebral artery (RMCA) of four cynomolgus monkeys; four unoperated animals served as controls. Arteriography was performed before and 7 days after surgery to assess the presence and degree of vasospasm, which was quantified in the anteroposterior (AP) projection by computerized image analysis. On Day 7, cortical cerebral blood flow (CBF) in the distribution of the right MCA was measured during four to six runs in the right internal carotid artery (ICA) of brief infusions of saline followed by NO solution. Arteriography was performed immediately after completing the final NO infusion in three of the four animals with vasospasm. Right MCA blood flow velocities were obtained using transcranial Doppler before, during, and after NO infusion in two vasospastic animals. After ICA NO infusion, arteriographic vasospasm resolved (mean percent of preoperative AP area, 55.9%); that is, the AP areas of the proximal portion of the right MCA returned to their preoperative values (mean 91.4%; range 88%–96%). Compared to ICA saline, during ICA NO infusion CBF increased 7% in control animals and 19% in vasospastic animals (p < 0.002) without significant changes in other physiological parameters. During NO infusion, peak systolic right MCA CBF velocity decreased (130 to 109 cm/sec and 116 to 76 cm/sec) in two vasospastic animals. The effects of ICA NO on CBF and CBF velocity disappeared shortly after terminating NO infusion. Intracarotid infusion of NO in a primate model of vasospasm 1) increases CBF, 2) decreases cerebral vascular resistance, 3) reverses arteriographic vasospasm, and 4) decreases CBF velocity in the vasospastic artery without producing systemic hypotension. These findings indicate the potential for the development of targeted therapy to reverse cerebral vasospasm after SAH.

Evidence against leukotrienes as mediators of brain edema

1991 ◽  
Vol 74 (5) ◽  
pp. 773-780 ◽  
Author(s):  
Andreas Unterberg ◽  
Walter Schmidt ◽  
Michael Wahl ◽  
Earl F. Ellis ◽  
Anthony Marmarou ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Brain Edema ◽  
Parietal Cortex ◽  
Brain Slices ◽  
Control Group ◽  
Tissue Water ◽  
Content Type ◽  
Cranial Window ◽  
Fine Print

✓ Leukotrienes are powerful metabolites of arachidonic acid which are known to increase the permeability of peripheral blood vessels. These substances are found in brain tissue in association with cerebral ischemia, and in brain tumors. Therefore, it has been proposed that leukotrienes have a mediator function in brain edema. This hypothesis was subjected to further experimental analysis in this study, in which the authors investigated whether: 1) superfusion of the exposed brain surface with leukotrienes increases the permeability of extraparenchymal blood vessels in vivo; 2) intraparenchymal infusion of leukotrienes induces brain edema; and 3) pharmacological inhibition of leukotriene formation by BW755C, an inhibitor of leukotriene synthesis, reduces formation of brain edema from a standardized traumatic insult. The pial vessels of the parietal cortex of cats were examined by fluorescence microscopy during cerebral superfusion with the leukotrienes C4 (LTC4), D4 (LTD4), or E4 (LTE4) by using an open cranial window preparation. Intravenous Na+-fluorescein served as an in vivo blood-brain barrier (BBB) indicator. Superfusion of the pia with leukotrienes (up to 2 µM) did not open the barrier to fluorescein, but was associated with a significant constriction (up to 25%) of arterial and venous vessels. In experiments with slow infusion of leukotriene B4 (LTB4) or LTC4 into the white matter of feline brain, the tissue water content was subsequently determined in serial brain slices using the specific gravity method. Tissue water profiles obtained after a 15- µM infusion of either LTB4 or LTC4 were virtually identical with those of control animals infused with mock cerebrospinal fluid. Thus, neither LTB4 nor LTC4 led to an augmentation of infusion-induced brain edema. In a final series, a cold lesion of the left parietal cortex was induced in rabbits. Twenty-four hours later, swelling of the exposed hemisphere was quantified by gravimetrical comparison of its weight with that of the contralateral nontraumatized hemisphere. Eight animals received BW755C intravenously prior to and after trauma to inhibit formation of leukotrienes. Seven rabbits were infused with an equivalent volume of saline as a control study. The resulting hemispheric swelling was 7.7% ± 0.6% (mean ± standard error of the mean) 24 hours later in animals receiving BW755C and 7.8% ± 1.2% in the control group, indicating that inhibition of leukotrienes was ineffective in preventing formation of vasogenic brain edema. The findings demonstrate that leukotrienes administered to the brain in concentrations occurring under pathological conditions do not open the BBB nor do they induce brain edema. Moreover, formation of brain edema from a standard insult was not therapeutically influenced by inhibition of leukotriene synthesis. Thus, the current findings taken together do not support a role of leukotrienes as mediators in brain edema.

In vitro and in vivo effects of probucol on hydrolysis of asymmetric dimethyl l-arginine and vasospasm in primates

2005 ◽  
Vol 103 (4) ◽  
pp. 731-738 ◽  
Author(s):  
Ryszard M. Pluta ◽  
Carla S. Jung ◽  
Judith Harvey-White ◽  
Anne Whitehead ◽  
Sabrina Shilad ◽  
...  
Keyword(s):  
Umbilical Vein ◽  
Oxidation Products ◽  
Cellular Mechanisms ◽  
Primate Model ◽  
Double Blind ◽  
Content Type ◽  
Delayed Cerebral Vasospasm ◽  
Fine Print

Object. Increased cerebrospinal fluid (CSF) levels of asymmetric dimethyl l-arginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase (eNOS), are associated with delayed vasospasm after subarachnoid hemorrhage (SAH); however, the source, cellular mechanisms, and pharmacological inhibition of ADMA production following SAH are unknown. Methods. In an in vitro experiment involving human umbilical vein endothelial cells (HUVECs), the authors examined mechanisms potentially responsible for increased ADMA levels during vasospasm and investigated whether this increase can be inhibited pharmacologically. In a second study, an in vivo experiment, the authors used probucol, which effectively inhibited ADMA increase in HUVEC cultures in vitro, in a randomized double-blind placebo-controlled experiment in a primate model of delayed cerebral vasospasm after SAH. Oxidized low-density lipids (OxLDLs; positive control; p < 0.02) and bilirubin oxidation products (BOXes; p < 0.01), but not oxyhemoglobin (p = 0.74), increased ADMA levels in HUVECs. Probucol inhibited changes in ADMA levels evoked by either OxLDLs (p < 0.001) or BOXes (p < 0.01). Comparable changes were observed in cell lysates. In vivo probucol (100 mg/kg by mouth daily) did not alter serum ADMA levels on Days 7, 14, and 21 after SAH compared with levels before SAH, and these levels were not different from those observed in the placebo group (p = 0.3). Despite achieving therapeutic levels in plasma and measurable levels in CSF, probucol neither prevented increased CSF ADMA levels nor the development of vasospasm after SAH. Increased CSF ADMA and decreased nitrite levels in both groups were strongly associated with the degree of delayed vasospasm after SAH (correlation coefficient [CC] 0.5, 95% confidence interval [CI] 0.19–0.72, p < 0.002 and CC −0.43, 95% CI −0.7 to < 0.05, p < 0.03, respectively). Conclusions. Bilirubin oxidation products, but not oxyhemoglobin, increased ADMA levels in the HUVEC. Despite its in vitro ability to lower ADMA levels, probucol failed to inhibit increased CSF ADMA and decreased nitrite levels, and it did not prevent delayed vasospasm in a primate SAH model.

Cerebral perivascular nerves in subarachnoid hemorrhage

1986 ◽  
Vol 65 (4) ◽  
pp. 531-539 ◽  
Author(s):  
Hideaki Hara ◽  
Michael Nosko ◽  
Bryce Weir
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Blood Clot ◽  
Autologous Blood ◽  
Nerve Fibers ◽  
Content Type ◽  
Arterial Blood ◽  
Mild Reduction ◽  
Perivascular Nerves ◽  
Basilar Arteries ◽  
Repeat Angiography

✓ The authors have studied the changes induced by subarachnoid hemorrhage (SAH) in the density and distribution of cerebral perivascular nerves in monkeys and rats. The SAH was induced in monkeys by placement of an autologous blood clot after opening the basal cisterns over the arteries of the circle of Willis on one side. In the rat study, SAH was induced by injection of autologous arterial blood into the cisterna magna. The nerves examined were adrenergic nerves, acetylcholinesterase (AChE)-containing nerves, vasoactive intestinal polypeptide (VIP)-like immunoreactive nerves, and substance P-like immunoreactive nerves. In the monkey study, all animals underwent baseline cerebral angiography, then had repeat angiography just before sacrifice on Day 2, 7, 28, or 70 after SAH. Two sham-operated monkeys underwent the surgical procedure without clot placement and were sacrificed on postoperative Day 7, after repeat angiography. Clot placement in monkeys reduced staining of all middle cerebral artery (MCA) perivascular nerves for between 2 and 28 days post-SAH. The number of stained nerve fibers of MCA's on the non-operated side was slightly reduced on Days 2 and 7 after SAH. Sham-operated monkeys showed a mild reduction of staining in all nerves, but only on the operated side. Cerebral vasospasm was observed on all angiograms taken on Days 2 and 7 following SAH. No vasospasm was found in normal or sham-operated monkeys. The disappearance of nerve staining without associated vasospasm was found on the operated side of the sham-operated monkeys and on the clot side of the animal sacrificed on Day 28 after SAH. Rats sacrificed on Days 2 and 7 post-SAH showed reduction in adrenergic and VIP-like immunoreactive staining around basilar arteries, while nerves containing AChE were not affected. Saline-injected rats exhibited no change in the appearance of perivascular innervation. These results suggest that SAH as well as surgical manipulation of the vessel wall caused a reduction of the studied substances in cerebral perivascular nerves. This reduction in immunoreactive staining of perivascular nerves did not correlate with the development of angiographic vasospasm after SAH.

Cerebral arterial pathology in experimental subarachnoid hemorrhage

1983 ◽  
Vol 58 (6) ◽  
pp. 843-850 ◽  
Author(s):  
Tetsumori Yamashima ◽  
Shinjiro Yamamoto
Keyword(s):  
Smooth Muscle ◽  
Subarachnoid Hemorrhage ◽  
Smooth Muscle Cells ◽  
Morphological Changes ◽  
Autologous Blood ◽  
Cerebral Arteries ◽  
Muscle Cells ◽  
Internal Elastic Lamina ◽  
Content Type ◽  
Fine Print

✓ Pathological changes of the cerebral arteries were studied in 30 dogs after subarachnoid injections of saline, fresh autologous blood, epinephrine, blood plus epinephrine, norepinephrine, or blood plus norepinephrine. Macroscopically, the circle of Willis was maximally dilated after the injection of epinephrine and was constricted following administration of blood plus epinephrine. Microscopically, neither saline nor blood produced abnormalities, except for minor changes of the adventitia in the latter. Epinephrine produced frank necrosis of smooth-muscle cells, which was subsequently replaced by fibrosis in the media of larger subarachnoid arteries, and the leakage of necrotic material from the infarcted hypothalamus contributed to these lesions. Blood plus epinephrine produced marked changes in the internal elastic lamina and tortuosities of the nuclei of smooth-muscle cells, while norepinephrine and blood plus norepinephrine produced only minor changes. Previously reported findings of morphological changes due to vasospasm after subarachnoid hemorrhage were confirmed experimentally, but such changes were found only after application of epinephrine. It is suggested that epinephrine produced the most severe vasospasm among the five substances tested.

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